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Biomedical subjects

H H Lu

Publications and source records attributed to H H Lu.

58 records · Page 4Linked to original sources
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The Baylor College of Medicine experience with gold seed implantation.

Advances in imaging technology and implant technique have led to the resurgent interest and practice of brachytherapy for the treatment of prostate cancer. Brachytherapy is a form of radiation treatment in which radioactive sources are placed directly into the tumor; it offers the advantage of maximizing the radiation dose delivered to the tumor while sparing the adjacent normal tissue. Permanent implants have become an important component of radiation delivery. Interstitial gold radioisotope (Au-198) implants for prostate cancer were introduced at Baylor College of Medicine in 1965. The rationale for using Au-198, instead of the two most commonly used radioisotopes, Palladium-103 (Pd-103) and Iodine-125 (I-125), is discussed, and the Baylor implant technique is compared to that used in other centers. Retrospective review divides the patient population into pre-ultrasound versus post-ultrasound eras. Dosimetric calculation and disease control with the Au-198 seed implant for prostatic cancer are reviewed for the two different eras; toxicity is evaluated in the post-ultrasound era only. In the pre-ultrasound era, 510 patients were treated with pelvic lymph node sampling and gold seed insertion of the prostate followed by external beam radiation. In the post-ultrasound era, 54 patients were treated definitively with ultrasound-guided transperineal Au-198 implant followed by external beam irradiation. A small group of 30 patients in the post-ultrasound era were evaluated for the efficacy of Au-198 re-implantation for locally recurrent disease.

Adult↗
PubMedDate not supplied

The potential use of intensity modulated radiotherapy (IMRT) in women with pectus excavatum desiring breast-conserving therapy.

The purpose of this study was to determine if intensity modulated radiation therapy (IMRT) offers a better treatment plan compared to conventional radiotherapy for patients with pectus excavatum desiring breast-conserving therapy and to assess the feasibility of simultaneous modulated accelerated radiation therapy (SMART) boost. A patient with pectus excavatum desired breast-conserving therapy for her early stage breast cancer. She underwent lumpectomy and axillary lymph node dissection followed by chemotherapy. She was then referred for radiotherapy. A breast board (Med-Tec) with aquaplast body cast was used to limit the movement of the patient, chest wall, and breasts before planning a computed tomography (CT) scan. IMRT including dose-volume histogram (DVH) was compared to that of the conventional plan using parallel opposed tangential beams with a 15-degree wedge pair. Forty-five gray was prescribed to the whole breast to each plan, while 50 Gy was prescribed to the tumor bed using IMRT with SMART boost in 25 fractions over 5 weeks. The coverage of the whole breast was adequate for both plans. IMRT allowed a more homogeneous dose distribution within the breast at the desired dose range. With IMRT there is less volume of ipsilateral lung receiving the radiation dose that is above the tolerance threshold of 15 Gy when compared to that of the conventional plan. However, there is more volume of surrounding normal tissues (the heart, spinal cord, and contralateral breast and lung) receiving low-dose irradiation when IMRT was employed. SMART boost was feasible, allowing a mean dose of 57 Gy to be delivered to the tumor bed simultaneously along with the rest of the breast in 5 weeks. IMRT is feasible in treating early breast cancer patients with pectus excavatum by decreasing the ipsilateral lung volume receiving high-dose radiation when compared to the conventional method. SMART boost shortens the overall treatment time that may have potential radiobiological benefit.

Adult↗